FIG. 1 is a fragmentary view of a typical loader/backhoe 10 having a shovel mechanism 12, stabilizer arms 14 and 16, and associated stabilizer pads 18 and 20, respectfully. Hydraulic pistons 15 are used to operate each of the stabilizer arms 14 and 16 independently. In FIG. 1, the stabilizer arms are in an operational, extended position with the stabilizer pads 18 and 20 in engagement with the ground surface to prevent movement of the backhoe during operation of the shovel mechanism 12. When the backhoe 10 is to be moved, the pistons associated with each cylinder are withdrawn so that the stabilizer arms 14 and 16 pivot and raise the stabilizer pads above ground level.
The stabilizer pad 18 of FIG. 1 is shown in greater detail in FIGS. 2 and 3. Stabilizer pad 20 is substantially identical to stabilizer pad 18. The stabilizer pad 18 and similar stabilizer pads are further described in U.S. Pat. Nos. 4,889,362, 5,054,812, 5,466,004, 5,547,220 and 5,667,245, each of which is issued to the inventor of the present application and incorporated herein by reference. The stabilizer pad 18 includes a flat plate 22 having flanges 24 and 26, both extending from one surface of plate 22. The stabilizer pad 18 is also provided with supporting webs or ribs 25, one associated with each flange. The ribs 25 provide additional support for the flanges 24 and 26. The plate 22 is notched at 30 between flanges 24 and 26 as illustrated in FIG. 1. The plate is notched to accommodate the arm 14 and to enable reversible rotation of the stabilizer pad.
The stabilizer arm 14 includes a journal end for accommodating pin 34. Pin 34 also fits within holes of flanges 24 and 26. The pin is used to secure the stabilizer pad to the arm using, for example, a cotter pin as illustrated in FIG. 3.
On the side of the flat plate 22 opposite that containing the flanges 24 and 26 are disposed three laminated rubber pads 40. Each of the rubber pads 40 includes laminated rubber sections supported between angle irons 44 and 48. The angle irons 44 and 48 have a base leg and an upright leg. Each of the upright legs has holes therein for receiving elongated securing pins 50 for containing the laminated rubber sections between the angle irons. The laminated pads 40 are secured to the plate 22 using bolts 53 and nuts 55.
The stabilizer pads 18 and 20 are rotatable about pin 34 when the stabilizer arms are in the raised position to place either the rubber pads 40 downward for engagement with the ground or to place the flanges 24 and 26 downward for engagement with the ground.
In typical operation, the rubber pad side of the stabilizer pad 18 is positioned to engage the ground, as shown in FIG. 1, when the ground surface is a relatively flat hard surface such as concrete or pavement. The flange side of the stabilizer pad 18, as shown in FIG. 2, is positioned to engage the ground when the ground surface is an unfinished ground surface, such as gravel or dirt. The flanges are designed to dig into the unfinished ground surface to anchor and stabilize the backhoe.
Although the prior art, reversible stabilizer pads described above provide reliable operation, it is desirable to provide a simplified stabilizer pad with improved operational performance over the stabilizer pads described above.